This is a breakout board for the TI TXB0104 bi-directional signal level shifter with automatic direction sensing. The TXB0104 features four channels of input/output signals and an output-enable line that allows the signal lines to be placed in a high-impedance mode when they are unneeded.

Depending on the high and low side voltages, the bandwidth on the individual signal channels can range from 20Mbps up to 100Mbps, making the TXB0104 suitable for higher-speed signals such as SPI.

This 4-bit non-inverting translator uses two separate configurable power supply rails. The A port is designed to track VCCA, which accepts any supply voltage from 1.2V to 3.6V. The B port is designed to track VCCB, which accepts any supply voltage from 1.65V to 5.5V.

This allows for universal low-voltage bi-directional translation between any of the 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, and 5V voltage nodes. VCCA should not exceed VCCB!

Each pin of the TXB0104 chip is broken out, giving you easy access to both the A and B ports.

Voltage Translator Board Features

1.2V to 3.6V on A Port and 1.65V to 5.5V on B Port (VCCA ≤ VCCB)

VCC Isolation Feature — if either VCC input is at GND, all outputs are in the high-impedance state

OE Input Circuit Referenced to VCC

Low Power Consumption, 5µA Max ICC

Board Overview

1. Output Enable Jumper is closed by default, causing the signals on both sides to be driven at all times. It's up to you to ensure that the system avoids bus contention states where the high side and low side of the same signal are being driven to opposite levels.

2. B-side Signals are the higher-voltage signals (VccB must be a higher voltage than VccA). The voltage range for VccB is 1.65V to 5.5V. If driving the OE pin from the high-voltage device, you should insert a 1k resistor in series with the drive signal.

3. A-side Signals are the lower-voltage signals (VccA must be a lower voltage than VccB). The voltage range for VccA is 1.2V to 3.6V.